PSLE Figure 1 shows a trapezium which has a perimeter of 47 cm. Shannon joins three such trapeziums to form Figure 2 which has a perimeter of 101 cm.
- Find the length of AB.
- Shannon joins another four such trapeziums to form Figure 3 which has an area of 460 cm2. Find the length of XY.
(a)
Perimeter of three separate trapeziums
= 3 x 47
= 141 cm
Number of overlapping ABs = 4
Length of 4 ABs
= 141 - 101
= 40 cm
Length of 1 AB
= 40 ÷ 4
= 10 cm
(b)
Area of 2 rectangles
= 460 ÷ 2
= 230 cm
2 Length of the rectangle
= 230 ÷ 10
= 23 cm
Length of XY
= 23 - 10 - 6
= 7 cm
Answer(s): (a) 10 cm; (b) 7 cm